Pangaribuan, Firman, and Rut K Pangaribuan. “PENGEMBANGAN ALAT PERAGA DARI LIMBAH PLASTIK UNTUK MATERI GEOMETRI BIDANG DATAR JENJANG SEKOLAH DASAR [CREATING TEACHING AID FROM PLASTIC WASTE ON PLANE GEOMETRY IN ELEMENTARY SCHOOL]”. JOHME: Journal of Holistic Mathematics Education 5, no. 1 (June 29, 2021): 31–43. Accessed March 14, 2025. https://ojs.uph.edu/index.php/JOHME/article/view/3528.